AP Physics 2 nuclear decay and mass-energy study guide

What type of decay involves helium nuclei?

Alpha decay emits an alpha particle (2 protons, 2 neutrons) from the nucleus.

True or False: Beta decay decreases atomic mass. Why?

False. Beta decay changes a neutron to a proton, increasing atomic number but not mass.

Alpha decay equation example?

$\displaystyle ^{238}_{92}U \rightarrow { }^{234}_{90}Th + { }^{4}_{2}He$

What particle is emitted during beta decay?

A beta particle, which is an electron or positron.

Fill in the blank: Alpha decay typically occurs in _______ elements.

heavy

What type of radiation is gamma decay?

Gamma decay emits high-energy photons (gamma rays) without changing the nucleus.

List two properties of alpha particles.

- Low penetration (stopped by paper) - High ionization power.

What is the main effect of gamma decay?

It releases energy without changing the number of protons or neutrons.

Compare alpha and beta decay in terms of mass change.

Alpha decay decreases mass (emits particles), beta decay does not change the mass.

True or False: Beta particles are heavier than protons.

False. Beta particles (electrons) are much lighter than protons.

Alpha decay is common in which type of isotopes?

Heavy isotopes like Uranium-238.

What is the result of beta-plus decay?

A proton is converted into a neutron, emitting a positron.

Equation for beta decay example?

$\displaystyle ^{14}_{6}C \rightarrow { }^{14}_{7}N + { }^{0}_{-1}e$

Fill in the blank: Gamma decay occurs after _______ decay.

alpha or beta

What energy relationship is involved in nuclear decay?

Mass-energy equivalence: $\displaystyle E = mc^2$.

What is a common use of gamma rays?

Medical imaging and cancer treatment.

What is mass-energy equivalence?

Mass-energy equivalence states that mass can be converted into energy and vice versa, expressed by the equation $\displaystyle E = mc^2$.

What does $\displaystyle E$ represent in $\displaystyle E = mc^2$?

$\displaystyle E$ represents energy measured in joules.

What does $\displaystyle m$ stand for in $\displaystyle E = mc^2$?

$\displaystyle m$ stands for mass measured in kilograms.

What does $\displaystyle c$ represent in $\displaystyle E = mc^2$?

$\displaystyle c$ represents the speed of light in vacuum, approximately $\displaystyle 3.00 imes 10^8$ m/s.

True or False: Mass can increase in nuclear reactions.

True. Mass can be lost and converted to energy during nuclear reactions.

What is mass defect?

Mass defect is the difference between the mass of a nucleus and the sum of its individual nucleons' masses.

Calculate the energy released from 0.1 kg of mass.

Using $\displaystyle E = mc^2$, $\displaystyle E = 0.1 imes (3.00 imes 10^8)^2 = 9.00 imes 10^{16}$ joules.

Cause → Effect: What happens when mass is lost in a reaction?

Energy is released, as mass is converted to energy according to $\displaystyle E = mc^2$.

What is the application of mass-energy equivalence in nuclear fission?

In nuclear fission, a heavy nucleus splits into lighter nuclei, releasing energy due to mass defect.

Fill in the blank: In nuclear fusion, nuclei combine, resulting in ______ energy output.

higher

Comparison: Fission vs Fusion.

- Fission: Splitting heavy nucleus. - Fusion: Combining light nuclei. - Both release energy based on mass-energy equivalence.

What is the significance of the speed of light in mass-energy equivalence?

The speed of light squared ($\displaystyle c^2$) indicates a large amount of energy can be produced from a small amount of mass.

True or False: Energy can exist without mass.

True. Energy can exist as electromagnetic radiation, which has no mass.

What equations are used to calculate energy in nuclear reactions?

$\displaystyle E = mc^2$ for mass-energy and $\displaystyle Q = E_{ ext{final}} - E_{ ext{initial}}$ for energy changes.

What is a practical example of mass-energy conversion?

In nuclear power plants, the fission of uranium converts mass into energy to generate electricity.

What is the relationship between binding energy and mass defect?

Binding energy is the energy equivalent of the mass defect, indicating stability of the nucleus.